At
Bis' final concert on July 8, 2014, Megumi Koshōji announced that she would form a new idol group. On November 5, the final line-up was revealed. The group released their debut studio album,
Bath Room, on September 23. followed by the single "River (Cloudy Irony)" on November 30, which would be their first release under
Tokuma Shoten. Their second album,
Image, was released on April 5, 2017. The single "412" was released on July 19, 2017, followed by "Cotoeri" on December 13,{{cite web|url=https://realsound.jp/2017/11/post-127161.html|title=Maison book girl、人工知能とサクライケンタ共同制作の新曲「言選り」MV公開 ==Members==